HAL Id: inserm-00593506
https://www.hal.inserm.fr/inserm-00593506
Submitted on 16 May 2011
HAL is a multi-disciplinary open access
archive for the deposit and dissemination of
sci-entific research documents, whether they are
pub-lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.
L’archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d’enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.
Impact of diabetes on work cessation: data from the
GAZEL cohort study.
Eléonore Herquelot, Alice Guéguen, Sébastien Bonenfant, Rosemary
Dray-Spira
To cite this version:
Eléonore Herquelot, Alice Guéguen, Sébastien Bonenfant, Rosemary Dray-Spira. Impact of diabetes on
work cessation: data from the GAZEL cohort study.: Impact of diabetes on work cessation. Diabetes
Care, American Diabetes Association, 2011, 34 (6), pp.1344-9. �10.2337/dc10-2225�. �inserm-00593506�
Impact of Diabetes on Work Cessation
Data from the GAZEL cohort study
ELÉONOREHERQUELOT,MSCALICEGUÉGUEN,PHD
SÉBASTIENBONENFANT,BS
ROSEMARYDRAY-SPIRA,MD, PHD
OBJECTIVE—To measure the impact of diabetes on work cessation, i.e., on the risks of work disability, early retirement, and death while in the labor force.
RESEARCH DESIGN AND METHODS—We used data from the GAZEL prospective cohort of 20,625 employees of the French national gas and electricity company“EDF-GDF.” We identified 506 employees with diabetes and randomly selected 2,530 nondiabetic employed control subjects matched for major socio-demographic and occupational characteristics. Using a multistate Cox model, we estimated hazard ratios (HR) comparing the risks of transition from employment to disability, retirement, and death over time between participants with versus without diabetes.
RESULTS—Employment rate decreased more rapidly in participants with diabetes (51.9 and 10.1% at 55 and 60 years, respectively) compared with nondiabetic participants (66.5 and 13.4%, respectively). Participants with diabetes had significantly increased risks of transition from employment to disability (HR 1.7 [95% CI 1.0–2.9]), retirement (HR 1.6 [1.5–1.8]), and death (HR 7.3 [3.6–14.6]) compared with participants without diabetes. Between 35 and 60 years, each participant with diabetes lost an estimated mean time of 1.1 year in the workforce (95% CI 0.99–1.14) compared with a nondiabetic participant.
CONCLUSIONS—Our results provide evidence for a profound negative impact of diabetes on workforce participation in France. Social and economic consequences are major for patients, employers, and society, a burden that is likely to increase as diabetes becomes more and more common in the working-aged population.
W
orldwide, 285 million people aged 20–79 years are estimated to have diabetes in 2010, and the preva-lence is expected to rise substantially in the coming decades (1). Diabetes confers an increased risk of disability (2–4). More-over, complications of diabetes constitute major causes of morbidity—ranging from visual impairment to amputation to coro-nary heart disease and premature mortality (1).Diabetes most often appears in middle-aged adults, and the majority of individuals diagnosed with diabetes are of working age (1). Several studies have shown that em-ployment rate of people with diabetes is substantially reduced compared with the nondiabetic population in the U.S., with major economic consequences (5–8). Un-derstanding the processes leading to such a
reduced employment rate in the growing population of people with diabetes may provide insights into strategies for limiting the burden of the disease for individuals and society, although prospective studies aimed at understanding these processes have remained limited. Data from the Health and Retirement Study in the U.S. suggested that among working-aged indi-viduals, work cessation occurred more fre-quently in those with diabetes versus those without prevalent diabetes at baseline in 1992 (9) as a result of higher rates of dis-ability, retirement, and premature death (10). However, these analyses were re-stricted to the prevalent cases of diabetes that were followed during a limited amount of time, and they did not account for occu-pational characteristics before diabetes occurrence. Thus they do not provide an
accurate estimate of the overall relative bur-den of diabetes on work cessation.
The current study aimed at quantifying the impact of diabetes on work cessation. More specifically, our objectives were 1) to prospectively measure diabetes-associated risks of work disability, early retirement, and premature death from the time of dia-betes onset, accounting for differences in oc-cupational characteristics before diabetes onset and 2) to estimate the amount of time lost in employment for individuals with diabetes compared with those without diabetes.
RESEARCH DESIGN AND METHODS
Study design
The GAZEL cohort was established in 1989 among employees of the French national electricity and gas company ”EDF-GDF.” In January 1989, all male employees, then aged 40–50 years, and all women employees, then aged 35–50 years, were invited to participate in the cohort. Of the 44,922 subjects (31,411 men and 13,511 women) asked to partic-ipate, 20,625 (45.9%) accepted: 15,011 men and 5,614 women. Higher participa-tion was associated with male sex, being married, having children, holding a mana-gerial status, and residing in some regions of France (11). EDF-GDF employees hold civil-servant–like status that entails job se-curity. Typically, they are hired when they are in their 20s and stay with the company until retirement. Since enrollment, they have been followed prospectively through a yearly self-administered questionnaire, including a large set of information on health—such as self-reported diabetes— and its determinants. Less than 1% of the participants has been lost to follow-up since 1989 (11).
Study population
In this study, we included GAZEL partic-ipants free of diabetes at baseline in 1989 who were subsequently classified as pa-tients with diabetes during follow-up since they were still employed and a matched sample of nondiabetic participants.
Participants were classified as patients with diabetes if they consistently self-re-ported diabetes in the yearly questionnaire.
c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c
INSERM, UMRS, CESP, Epidemiology of Occupational and Social Determinants of Health, Villejuif, France; and University of Versailles Saint-Quentin, UMRS, Villejuif, France.
Corresponding author: Rosemary Dray-Spira, rosemary.dray-spira@inserm.fr. Received 25 November 2010 and accepted 26 March 2011.
DOI: 10.2337/dc10-2225
© 2011 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. See http://creativecommons.org/ licenses/by-nc-nd/3.0/ for details.
care.diabetesjournals.org DIABETESCARE 1
Consistent report of diabetes was defined based on the combination of response rate to the yearly questionnaire and frequency of self-reports of diabetes in the completed questionnaires. Those reporting diabetes inconsistently across time (i.e., less than once every 3 years following the first occurrence of self-reported diabetes) were classified as nondiabetic participants. For participants classified as patients with di-abetes, the year of diabetes onset was that of thefirst occurrence of self-reported diabe-tes if the questionnaire of the preceding year indicated the absence of diabetes. In the case of missing questionnaires between the last year with no diabetes reported and the first year with diabetes reported, the year of diabetes onset was randomly as-signed between these 2 years.
Nondiabetic participants were matched to those with diabetes for major socio-demographic and occupational de-terminants of workforce participation, i.e., sex and characteristics at the time of hiring in EDF-GDF, including calendar year, age, and occupational grade. Non-diabetic referents also had to be employed at the time they were matched to partic-ipants with diabetes. Five nondiabetic participants were randomly matched to each participant with diabetes.
Variables of interest
We obtained information on occupa-tional status throughout the career in EDF-GDF (including characteristics at the time of hiring, retirement date, pen-sion for disability or longstanding illness, and sickness absences) as well as on mortality from the company administra-tive records. Because retirement pensions are paid by EDF-GDF, these records pro-vide comprehensive and accurate infor-mation. Legal age of retirement for EDF-GDF employees is between 55 and 60 years, mainly depending on the type of job: manual/unskilled workers are al-lowed to retire earlier. Participants were considered in disability if they had been granted a pension for disability or long-standing illness or if they had sick leave of more than 365 days.
BMI at age 50 years was obtained using self-reported height and weight and categorized as normal or underweight (,25.0 kg/m2), overweight (25.0-29.9
kg/m2), or obese (30.0 kg/m2or more). Statistical analysis
Analysis was based on data collected as of 31 December 2007 and restricted to the age range of 35–60 years. Participants
with diabetes were accounted for in the nonexposed group until diabetes onset and then in the exposed group starting from the year of diabetes onset. Probabil-ities of disability, retirement, and death at each point of the age range were estimated separately for participants with and with-out diabetes using the Kaplan-Meier method. Using a multistate Cox model, we estimated hazard ratios (HR) compar-ing the risks of transition from employ-ment to each of these categories of inactivity between participants with ver-sus without diabetes. These HR automat-ically accounted for characteristics used as matching criteria. In addition, further adjustment for BMI at age 50 years was performed. The proportional hazard hy-pothesis was verified based on the corre-lation between Schoenfeld residuals and time. Using the predicted probabilities of being in each of the four states of the model over time, we then estimated the difference in the amount of time spent out of the workforce between 35 and 60 years according to diabetes status. Confidence interval of this difference was estimated using the bootstrap percentile method.
Statistical analyses were performed using SAS 9.1 and R software with the packages survival and mstate.
RESULTS
Sample characteristics
Among the 20,625 participants included in the GAZEL cohort, 20,318 reported that they were free of diabetes in the baseline self-questionnaire in 1989. Among them, 981 were subsequently classified as patients with diabetes during follow-up. Of these 981 participants with incident diabetes, 508 were still em-ployed at the time of diabetes onset and were thus considered as the exposed group in our study. Two of them were excluded because they did not have non-diabetic counterparts with comparable characteristics with regard to matching criteria, and each of the 506 remaining was matched to five nondiabetic partic-ipants. Thus thefinal sample consisted of 3,036 participants: 506 with diabetes and 2,530 without diabetes. As of 31 Decem-ber 2007, 3.5% of these 3,036 partici-pants were dead, 89.6% were retired, 0.8% were disabled, and 6.1% were still employed.
Characteristics of the study popula-tion according to diabetes status are shown in Table 1. As in the entire cohort, participants were mostly men. Half of
them had been hired in EDF-GDF in the years 1957–1966 as they were in their 20s (mean age 22.8 years). The large majority (over 80%) had been hired on a low oc-cupational position, i.e., either as manual workers or clerks. Upward occupational mobility was frequent, and as a result, only a minority (29.8% of participants with diabetes and 24.3% of those without diabetes) were still holding a low occupa-tional position at 35 years.
Among the 506 participants with di-abetes, mean age at diabetes onset was 51.6 years (minimum: 39; maximum: 60 years). At age 50 years 190 participants had diabetes; this number was 427 at age 55 years and 506 at age 60 years. Almost half (45.6%) of participants with diabetes were overweight, and one third (33.4%) were obese at 50 years. This was the case only for 40.7 and 5.7% of nondiabetic participants, respectively.
Employment status of participants with and without diabetes over time All of the 3,036 participants were em-ployed as they were aged 35 years, and the large majority (95.3% of those with diabetes and 96.4% of those without diabetes) were still working as they reached the age of 50 years. Subse-quently, employment rate decreased more rapidly in participants with diabe-tes (51.9 and 10.1% at ages 55 and 60 years, respectively) compared with those without diabetes (66.5 and 13.4%, re-spectively). At the age of 55 years, a higher proportion of participants with versus without diabetes were retired (39.5 vs. 28.2%, respectively; P , 0.001) or had died (2.9 vs. 1.1%, respec-tively; P = 0.003). At the age of 60 years, a higher proportion of participants with versus without diabetes were work dis-abled (5.0 vs. 1.4%, respectively; P , 0.001).
Frequency of work disability, retirement, and death over time Overall, between the ages of 35 and 60 years, work disability occurred in 15 employed participants with diabetes and 162 without diabetes; retirement oc-curred in 399 employed participants with diabetes and 2,222 without diabetes; death occurred in 13 employed partici-pants with diabetes and 22 without di-abetes (Table 2).
Figure 1 shows the probabilities of disability, retirement, and death by diabe-tes status at each point of the age range between 50 and 60 years— the period
2 DIABETESCARE care.diabetesjournals.org
during which most of the work cessation events occurred. Among both partici-pants with and without diabetes, the probabilities of disability, retirement, and death continuously increased with age, with a steep increase in the probabil-ity of retirement at 55 years. The increase in the probability of disability was
consistent across diabetes groups be-tween 50 and 54 years but steeper among participants with diabetes thereafter. Impact of diabetes on the risk of work cessation over time
As shown in Table 2, participants with diabetes had a significantly increased
probability of transition from employment to disability (HR 1.7 [95% CI 1.0–2.9]), to retirement (HR 1.6 [1.5–1.8]), and to death (HR 7.3 [3.6–14.6]) compared with partic-ipants without diabetes. After adjustment for BMI, the increase in the risks of retire-ment (HR 1.6 [1.5–1.8]) and death (HR 8.0 [3.8–17.0]) associated with diabetes re-mained unchanged, although the diabe-tes-associated risk of disability was reduced and no longer significant (HR 1.4 [0.8–2.4]). The impact of diabetes on dis-ability and death was consistent over time. In contrast, diabetes effect on retirement significantly decreased over time, with the HR decreasing (from HR 2.1 [1.7–2.5] to 1.5 [1.3–1.7]) between 35 and 55 years () thereafter when most of the participants re-tired regardless of diabetes status.
Between the ages of 35 and 60 years, we estimated that each participant with diabetes lost an average time of 1.1 years in the workforce (95% CI 0.99–1.14) compared with a nondiabetic participant, whose retirement accounted for 0.70 year of this loss (95% CI 0.62–0.78), death for 0.28 year (95% CI 0.20–0.35), and dis-ability for 0.09 year (95% CI 0.02–0.15). Sensitivity analysis
Our definition of diabetes, based on a pattern of consistent self-report, is likely to have excluded the milder cases of disease. To capture these less severe cases, analyses were repeated using an alterna-tive definition of diabetes in which all 773 cases with any mention of diabetes in the yearly questionnaire were classified as having diabetes, regardless of the consis-tency of this self-report. Although the effect of diabetes on disability was un-changed (HR 1.6 [95% CI 1.1–2.4]), the effects on retirement (HR 1.3 [1.1–1.4]) and death (HR 2.3 [1.2–4.2]) were lower than the estimates reported in Table 2. However, these effects remained signi fi-cant. Likewise, the estimated average time of lost employment among par-ticipants with diabetes was decreased
Table 1—Characteristics of the study population according to diabetes status Participants with diabetes Participants without diabetes n 506 2,530 Sex Men 419 (82.8) 2,095 (82.8) Women 87 (17.2) 435 (17.2)
Calendar year at the time of hiring in EDF-GDF
1957–1966 247 (48.8) 1,239 (49.0)
1967–1976 190 (37.6) 947 (37.4)
1977–1987 69 (13.6) 344 (13.6)
Age at the time of hiring in EDF-GDF (years)
15–19 170 (33.6) 873 (34.5)
20–29 262 (51.8) 1,303 (51.5)
30 or more 74 (14.6) 354 (14.0)
Occupational grade at the time of hiring in EDF-GDF
Managers or executives 47 (9.3) 235 (9.3)
Associates professionals or technicians 34 (6.7) 170 (6.7)
Clerks 189 (37.4) 945 (37.4)
Manual workers 232 (45.8) 1,160 (45.8)
Missing 4 (0.8) 20 (0.8)
Occupational grade at 35 years
Managers or executives 75 (14.8) 420 (16.6) Associates professionals or technicians 252 (49.8) 1,369 (54.1)
Clerks 66 (13.0) 290 (11.5)
Manual workers 85 (16.8) 325 (12.8)
Missing 28 (5.5) 126 (5.0)
Age at the time of diabetes onset (years)
35–44 28 (5.5) — 45–54 364 (71.9) — 55 or more 114 (22.5) — BMI at 50 years (kg/m2) Normal or underweight 97 (19.2) 1,217 (48.1) Overweight 231 (45.6) 1,030 (40.7) Obese 169 (33.4) 145 (5.7) Missing 9 (1.8) 138 (5.5) Values are n (%).
Table 2—Risk of work disability, retirement, and death among participants with diabetes compared with those without diabetes Participants with diabetes Participants without diabetes HR [95% CI] Number
of events
Incidence rate per 1,000 person-years
Number of events
Incidence rate per 1,000 person-years
Accounting for matching criteria*
Additionally adjusted for BMI at age 50 years Employment
to Disability 15 7.9 162 2.7 1.7 [1.0–2.9] 1.4 [0.8–2.4]
to Retirement 399 209.1 2,221 37.6 1.6 [1.5–1.8] 1.6 [1.5–1.8]
to Death 13 6.8 22 0.4 7.3 [3.6–14.6] 8.0 [3.8–17.0]
(0.59 year [0.52–0.66]) but remained significant.
CONCLUSIONS—Our results pro-vide epro-vidence for a profound negative impact of diabetes on workforce partici-pation in France. Indeed, we found that, among employees of the GAZEL cohort, diabetes is associated with an overall 60–70% increase in the risks of work dis-ability and early retirement and with a sevenfold increase in the risk of death while in the labor force. The effect of di-abetes on disability is largely attributable
to obesity. These substantially increased risks of work cessation associated with di-abetes translate into an absolute decrease of over 1 year spent in employment be-tween 35 and 60 years for employees with diabetes compared with those without diabetes. Retirement accounts for the major part (64%) of this difference.
Strengths of this study, which lend weight to these conclusions, include pro-spective data from a large occupational cohort, constituted of a diverse popula-tion of white- and blue-collar employees from all regions of France, with long-term
follow-up that is almost 100% complete. Available information on occupational sta-tus throughout the career in the company is particularly comprehensive and accurate since it has been obtained directly from the company administrative records. In addi-tion to ensuring highly reliable measures of the outcomes of interest, such informa-tion allowed us to account for occupainforma-tional characteristics early in an individual’s ca-reer in our analyses and thus to provide estimates of the burden of diabetes inde-pendent of these major occupational deter-minants of workforce participation.
Figure 1—Probability of work disability (A), retirement (B), and death (C) according to ages between 50 and 60 years among participants with (solid line) and without (dashed line) diabetes.
4 DIABETESCARE care.diabetesjournals.org
Our study has several limitations. First, information on diabetes was self-reported. Although accuracy of diabetes self-report is high (12), such a definition excludes undiagnosed cases of the dis-ease, which are incorrectly considered as free of diabetes. However, only 13% of diabetic adults aged 55–74 years are esti-mated to be undiagnosed in France (13). Moreover, to be considered as patients with diabetes, participants in our study had not only to self-report diabetes once during follow-up but also to consistently self-report the disease over time after the first report. This probably improved the identification of true cases of diabetes compared with a definition based on a unique occurrence of self-reported diabe-tes. Although our definition may have led to exclude some cases of diabetes episod-ically self-reported, internally consistent results are obtained using either defini-tion, as shown in our sensitivity analysis. In addition, available data did not allow us to distinguish between type 1 and type 2 diabetes. However, because our analy-ses were restricted to incident caanaly-ses of di-abetes occurring after enrollment in the GAZEL cohort, i.e., after the age of 35 years, our results mostly pertain to type 2 diabetes.
There are several considerations sug-gesting that the magnitude of diabetes impact on workforce participation may have been underestimated in our study. First, EDF-GDF employees have a partic-ularly high level of job security; moreover, some categories of workers (e.g., those self-employed and agricultural workers), whose occupational status may be partic-ularly vulnerable to health problems, are not represented in the company (11). Sec-ond, to provide valid estimates of the im-pact of diabetes on work cessation, our analyses were restricted to incident cases of diabetes appearing after enrollment in the cohort, i.e., later than 1989. Thus cases of diabetes that occurred earlier in employees’ careers were excluded. The impact of these early-onset cases on work cessation before 1989 could not be accounted for in our study since the GAZEL cohort was restricted to employ-ees still working in 1989. However, a complementary analysis suggested that the diabetes-related increase in the risk of disability during follow-up may be more marked for cases prevalent in 1989 (results not shown). Third, because a large proportion of EDF-GDF employees are given the opportunity to retire between 55 and 60 years, retirement before 55 years
rather than 60 years may constitute a bet-ter indicator of early retirement in this population. Diabetes-related increase in the risk of early retirement was substan-tially higher between 35 and 55 years (HR 2.1 [95% CI 1.7–2.5]) than between 35 and 60 years (HR 1.6 [95% CI 1.5–1.8]).
To our knowledge, this study is the first to provide evidence for a significant impact of diabetes on work cessation in France, a country with a system of uni-versal social protection. Our findings of increased risks of disability, retirement, and death among employees with versus without diabetes are consistent with re-ports based on data from the Health and Retirement Study in the U.S. (9,10). This shows that such deleterious consequen-ces of diabetes on workforce participation occur in the context of very different sys-tems of social protection.
Diabetes is unevenly distributed across socioeconomic strata, with higher prevalence of the disease reported in the most deprived groups of the population (14,15). This suggests that individuals with diabetes may be more prone than others to hold adverse occupational con-ditions, exposing them to an increased risk of unemployment. This could ex-plain, at least in part, the differences for-merly reported between individuals with versus without diabetes with regard to employment status (6–10,16). In our study, all participants were employed by the same company and thus benefited from a comparable level of job security; moreover, we were able to provide esti-mates accounting for occupational char-acteristics before diabetes onset. Thus our findings add significant knowledge to the existing literature by providing evidence for an independent effect of diabetes on work cessation.
Further research is needed to ascer-tain the generalizability of our results outside the GAZEL cohort study, and more generally outside France. The French pattern of early transitions out of employment is characterized by a low age of retirement and by the importance of transitions through unemployment in-surance and preretirement schemes, re-sulting in lower recourse to disability compared with other countries (17). De-spite these differences, data from SHARE (Survey on Health Ageing and Retirement in Europe) suggest that the overall burden of health impairment on work cessation does not differ in France compared with other European countries (18). This
suggests that although the patterns of transitions out of employment are likely to be country specific, the negative im-pact of diabetes on workforce participa-tion that we show might be fairly generalizable to other settings. Our re-sults pertain to the population of work-ing age, i.e., aged less than 60 years in France, a country with universal access to a high quality of medical care. The impact of diabetes on work cessation might be even greater in countries with older retirement ages or lower access to quality healthcare.
Diabetes can affect individuals’ ability to maintain employment through differ-ent pathways. This can happen directly through impairment of bodily functions arising from diabetes complications, in-cluding loss of vision, amputations, or mobility limitations (16,19); workplace discrimination encountered by employ-ees with diabetes may also play a role (20). Moreover, because diabetes is fre-quently associated with other health problems, comorbidities can constitute additional barriers to employment. Obe-sity has been shown to impair employ-ment status in several studies (21–24); in addition, our results suggest that differ-ences in BMI between employees with versus without diabetes explain a signif-icant part of the effect of diabetes on disability. Studies also suggest that mac-rovascular comorbid conditions (25) and depression (19) are associated with higher rates of unemployment among people with diabetes.
In conclusion, the current study pro-vides evidence that diabetes substantially weighs on employees’ chances of main-taining in employment. This effect of di-abetes has major social and economic consequences for patients, employers, and society, a burden that is likely to in-crease as diabetes becomes more and more common in the working-aged pop-ulation. Limiting the social and economic burden of diabetes is a major challenge to be addressed at different levels, including the health care system, employers, and social workers.
Acknowledgments—No potential conflicts of interest relevant to this article were reported.
E.H. ran all of the analyses and wrote the manuscript. A.G. provided statistical advice and reviewed and edited the manuscript. S.B. researched data and reviewed and edited the manuscript. R.D.-S. generated the study hy-pothesis and wrote the manuscript.
The authors thank members of the GAZEL cohort study who contributed data for this study. The authors also thank the GAZEL cohort study team responsible for overseeing data collection and EDF-GDF (Service des Etudes Médicales, Service Général de Médecine de Contrôle).
References
1. International Diabetes Federation. Di-abetes Atlas. 4th ed. Brussels, Belgium, International Diabetes Federation, 2009 2. Gregg EW, Beckles GL, Williamson DF,
et al. Diabetes and physical disability among older U.S. adults. Diabetes Care 2000;23:1272–1277
3. Sinclair AJ, Conroy SP, Bayer AJ. Impact of diabetes on physical function in older people. Diabetes Care 2008;31:233–235 4. Volpato S, Blaum C, Resnick H, Ferrucci
L, Fried LP, Guralnik JM; Women’s Health and Aging Study. Comorbidities and impairments explaining the association between diabetes and lower extremity disability: The Women’s Health and Aging Study. Diabetes Care 2002;25:678–683 5. Hogan P, Dall T, Nikolov P; American
Diabetes Association. Economic costs of diabetes in the US in 2002. Diabetes Care 2003;26:917–932
6. Mayfield JA, Deb P, Whitecotton L. Work disability and diabetes. Diabetes Care 1999; 22:1105–1109
7. Ng YC, Jacobs P, Johnson JA. Productivity losses associated with diabetes in the US. Diabetes Care 2001;24:257–261 8. Valdmanis V, Smith DW, Page MR.
Pro-ductivity and economic burden associated with diabetes. Am J Public Health 2001; 91:129–130
9. Tunceli K, Bradley CJ, Nerenz D, Williams LK, Pladevall M, Elston Lafata J. The
impact of diabetes on employment and work productivity. Diabetes Care 2005; 28:2662–2667
10. Vijan S, Hayward RA, Langa KM. The impact of diabetes on workforce partici-pation: results from a national household sample. Health Serv Res 2004;39:1653– 1669
11. Goldberg M, Leclerc A, Bonenfant S, et al. Cohort profile: the GAZEL Cohort Study. Int J Epidemiol 2007;36:32–39
12. Okura Y, Urban LH, Mahoney DW, Jacobsen SJ, Rodeheffer RJ. Agreement between self-report questionnaires and medical record data was substantial for diabetes, hypertension, myocardial in-farction and stroke but not for heart fail-ure. J Clin Epidemiol 2004;57:1096– 1103
13. Bonaldi C, Vernay M, Roudier C, et al. A first national prevalence estimate of di-agnosed and undidi-agnosed diabetes in France in 18- to 74-year-old individuals: the French Nutrition and Health Survey 2006/2007. Diabet Med. In press 14. Cowie C, Eberhardt M.
Sociodemo-graphic characteristics of persons with diabetes. In Diabetes in America. 2nd ed. Harris M, Cowie C, Stern M, Boyko E, Reiber G, Bennett P, Eds. Bethesda, MD, National Institute of Health, 1995, p. 85– 116
15. Espelt A, Borrell C, Roskam AJ, et al. So-cioeconomic inequalities in diabetes mel-litus across Europe at the beginning of the 21st century. Diabetologia 2008;51: 1971–1979
16. Kraut A, Walld R, Tate R, Mustard C. Impact of diabetes on employment and income in Manitoba, Canada. Diabetes Care 2001;24:64–68
17. Ben Salem M, Blanchet D, Bozio A, Roger M. Labour force participation by the
elderly and employment of the young: the case of France. In Social Security programs and retirement around the world: the re-lationship to youth unemployment. Gruber J, Wise D, Eds. Chicago, IL, NBER/The Uni-versity of Chicago Press, 2010
18. Barnay T, Debrand T. Effects of health on the labour force participation of older persons in Europe. Issues in Health Economics, 2006, p. 109
19. Von Korff M, Katon W, Lin EH, et al. Work disability among individuals with diabetes. Diabetes Care 2005;28:1326– 1332
20. McMahon BT, West SL, Mansouri M, Belongia L. Workplace discrimination and diabetes: the EEOC Americans with Dis-abilities Act research project. Work 2005; 25:9–18
21. Paraponaris A, Saliba B, Ventelou B. Obesity, weight status and employability: empirical evidence from a French national survey. Econ Hum Biol 2005;3:241–258 22. Renna F, Thakur N. Direct and indirect
effects of obesity on U.S. labor market outcomes of older working age adults. Soc Sci Med 2010;71:405–413
23. Rodbard HW, Fox KM, Grandy S; Shield Study Group. Impact of obesity on work productivity and role disability in in-dividuals with and at risk for diabetes mellitus. Am J Health Promot 2009;23: 353–360
24. Tunceli K, Li K, Williams LK. Long-term effects of obesity on employment and work limitations among U.S. Adults, 1986 to 1999. Obesity (Silver Spring) 2006;14: 1637–1646
25. Fu AZ, Qiu Y, Radican L, Wells BJ. Health care and productivity costs associated with diabetic patients with macrovascular comorbid conditions. Diabetes Care 2009; 32:2187–2192
6 DIABETESCARE care.diabetesjournals.org
